I am not really sure what you’re trying to communicate here, can you elaborate?
This is exactly how it works now.
They aren’t and they already can be detached (right-click → Disconnect).
By changing their ID? I guess it can be useful if user needs to make a bunch of exported nodes.
They already can be.
They already can be (to a certain degree, you cannot make them truly interlinkable without causing a recursion).
This makes sense, although it usually faster the regular way, because in most cases you need to connect one node to multiple parameters and dragging it across the screen every time isn’t very productive if you ask me. I personally vote for keyboard shortcut for ‘Connect’ action.
Cool idea but already requested. @Svarov the request is about connecting and duplicating nodes (valuenode/exported values) with some visual representation similar to node editor in Blender.
A issue on GitHub is already created, this is a hard to implement, will take more time, and would be a breaking change to Synfig.